The darkening of a woman’s stomach after pregnancy may be related to hyperpigmentation caused by hormonal changes, stretch marks during pregnancy and other reasons. 1. Hormonal changes caused by hyperpigmentation: During pregnancy, women will stimulate melanocytes to secrete more hormones, and also secrete a lot of estrogen and progesterone, which will stimulate the production of melanocytes, leading to the accumulation of melanin in the skin, causing the stomach to turn black. 2. Stretch marks: the enlargement of the uterus during pregnancy, the elastic fibers of the skin of the abdominal wall will break, resulting in the appearance of purple or reddish irregular stripes, that is, stretch marks, if the accumulation of the stomach may cause darkening. In addition, pregnant women may not only have darkened tummies, but also other parts of the body, such as the areola, abdomen, and armpits. At the same time, pregnant women do not need to worry too much, with the decline in hormone levels after delivery, hyperpigmented areas will slowly fade. If there is any obvious abnormality, you need to be actively diagnosed and treated.